> i've noticed this on my a-132-4
> i'm using mine as 4 separate vca's
> a negative voltage will no doubt close it more, but why the
> design i wonder

The A-132-4 VCAs have an exponential control scale. The A-132-4 information
on our website says "The control scale for each VCA is about 12dB/V (i.e. 1
V CV decrease corresponds to 12dB level decrease and 1 V CV increase
corresponds to 12dB level increase). 0V CV corresponds to about -60dB".
Consequently a negative voltage is required to attenuate more than -60dB.

Same applies to the A-132-3 in the exp. mode. As a rule exponential VCAs
have a certain attenuation/amplification specified in X dB/V. From the
theory one never reaches zero amplification (-OO dB) but in reality the
signal will vanish in the noise floor.

Best wishes
Dieter Doepfer